1. Field of the Invention
The present invention concerns a flat sealed sachet formed by two sheets which are sealed along their edges by a sealing strip defining a cavity receiving a liquid, pasty or powder product, the contour of said cavity being prolonged by a nose portion which intrudes into the sealing strip (non-sealed part).
2. Description of the Related Art
The flat sealed sachets of the type defined above enjoy many applications; they are primarily intended to receive a relatively small amount of a liquid, pasty or powder product which is used only in a small amount at a time. Such sachets are distributed in the form of promotional products intended to bring awareness of a production which is then sold in a different form of packaging such as a bottle but also as an individual portion which can be used as such and then the sachets are sold as single items or grouped together in another packaging.
These sachets are also packagings for food products which are used in small quantities such as for example a serving of vinaigrette or a serving of mayonnaise or mustard for certain forms of presentation of food products, for example plated meals for groups of people or fast food and so forth.
These sachets are formed in a complex multi-layer material (for example: pet/alu/pe, pet/alu/pet/pe, pet/pe, pet/paper/alu/pe), ensuring both sealing integrity of the sachet, generally opacity thereof and making it possible to seal the sachet for example by heat sealing of the peripheral edge portion of the sachet. That sealing operation is implemented with a hot stamping die of a certain width and of the shape of the contour of the sachet. In general the contour of the sachet is rectangular but it may also involve other fancy shapes, imitating a bottle or another packaging silhouette in which for example the product contained as a sample in the sachet is distributed.
The sealing strip of the sachet extending around the entire periphery of the sachet is produced in one or more operations using known processes and machines.
One of the difficulties involved in this form of packaging is that of opening the sachet, which can be very easily effected by means of a cutting tool such as a pair of scissors or a knife. Such opening means however are not always available and in particular it must be possible to open the sachet simply without a tool by tearing the sealed edge by hand.
However, as a certain pressure has to be applied to the two parts which are to be torn one from the other, that force has to be applied directly with the fingers to the cavity of the sachet or indirectly by a pulling force applied to the sachet. Compression of the volume of the cavity runs the risk at the moment of opening of the sachet of being abrupt and in particular random, causing some of the contents of the sachet to be abruptly ejected in a manner which is also unpredictable. Such an effect is not only troublesome because of the loss of product or the risk of staining that the ejected product can cause, but it also runs the risk of giving an adverse image for the packaging.
Various solutions have already been proposed for avoiding unforeseen opening in that way. One of the solutions involved consists of cutting into the sealing strip on one side of the sachet to create a rupture beginning or incipient rupture location which is enlarged at the moment of tearing it to pass through the sealing strip and then reach the location of the cavity to permit the product to be taken therefrom.
That known incipient rupture location can be disposed in line with the nose portion or spout portion which prolongs the cavity so that propagation of the tearing effect goes to a position in line with the pouring nose portion and cuts it to make it easier for the product contained in the cavity to be discharged therefrom without causing accidental sudden ejection thereof.
However, in order for that incipient rupture location to be effective for easily tearing open the sachet, having regard moreover to the high level of strength necessary for the material of the complex structure, that incipient rupture location must be of a sufficient length and the user must have a sufficient surface area on respective sides of the incipient rupture location to be able to hold the two parts of the sachet firmly. Different forms of cut have therefore been developed, starting from the incipient rupture location at the edge of the sachet and being of a greater or lesser length in order precisely to form gripping surfaces. However the length of those cuts which are no longer limited to a simple incipient rupture make the packaging more delicate and fragile since they cross a substantial part of the surface area or the width of the sealing strip. In addition even if the cut leaves a very thin connecting portion remaining (the cut not passing entirely through the whole thickness of the two layers of the complex material), that connecting portion is often torn away, the sachet part is bent back and the overall aesthetics are adversely affected.
There are also products which are not intended just for a single use but for two or three uses. This case involves profiting from the rigidity of the aluminium part of the complex material of the sachet to fold over the edge of the sachet and more or less re-close the nose portion. As the sachet is often set down flat or even if it is positioned more or less vertically, it runs the risk of slipping and adopting a flat position so that the product that it contains can ooze through the opening, even when it has been closed by being folded over, and it can give rise to stains.